Cleaning an incised coin

[traveler]

Hello all,

I just received this incised coin, but upon further inspection I realised there's quite a bit of (ancient?) crud or dirt inside the test cut. The dirt kind of bothers me, is there any safe way to clean it? I'd like to remove the dirt and weigh the coin again if possible.

The cut itself is too narrow for anything other than a fine needle or a bamboo skewer, but I certainly can't take a needle to this coin. I'm afraid even the bamboo skewer could leave scratches.

[SC]

Soak the coin in warm soapy water for a long time.  That shouldn't hurt gold at all.  Then crack some bamboo skewers in half.  You will get lots of very fine slivers that are not too hard.  You could also try sharpening bamboo skewers or tooth-picks (the round kind) with an x-acto blade and then using them.  I don't think they would scratch if you are gentle.  Use magnification so that you only apply pressure once they are in the crack.  Always start with the lightest touch and then apply a bit more force.

If nothing moves you can try repeated soakings to try to soften it.

However, there is always the chance that whatever is in the there has a hardness greater than the gold in which case there is nothing you could do short of a steel pin - which as you not e is not a good idea.

Shawn

[traveler]

Hi Shawn,

Thanks for the advice. In the end I used a very fine toothpick since it could fit in the incision. The bamboo skewer fragments were too soft to do the cleaning.

I tried soaking it in hot water first, and the dirt started to dissolve with some gentle pushing. It looks like part of it was mud. The problem is that there seems to be some harder stuff than mud in there, either that or its really compacted. The toothpick could only "glide" on the surface with the amount of force I was using.

Maybe I'll leave it sitting in hot water for a longer time and see if it improves. I took another photo of the coin to see if I scratched it: looks like no scratches, but not much improvement either. (Colour is a little different because I'm using natural light).

[Akropolis]

When in doubt, stop!
PeteB